Replacing an old toilet with an Ultramax II - how do I know if it will fit?

Can anyone please tell me how will I know if the bolt holes from the toilets i currently have and the size from the back of my current two piece toilet to the wall will work with the 1 piece Ultramax II?

I am desparate to swap out my 3 builder grade toilets but I am worried about holes not lining up and possibly having to replace some ceramic in all three bathrooms if the bolts don't align and the back of he 1 piece Ultramax II won't meet up with the back of the wall.

Hopefully everything has to meet standard size and this wil be a straight swap.

One thing remains uniform with toilets: The rough-in measure. If you measure from the flange bolts on your current toilet to the wall, that is the rough-in size no matter what the make, model, or year of your new toilet although most toilets will fit in slightly less space as their rated rough-in.

The waste rough-in for most toilets sold today is 12" from the flange slots for the toilet bolts to the FINISHED wall (not counting the baseboard, if it exists). What is NOT common in the industry, is the location of the water supply. Some toilets need it in a certain place, some are quite flexible. The manufacturer's spec sheet will show (typically, anyway) the IDEAL place for the water supply, but that does not mean it MUST be there. Each toilet is different in that respect, so you have to look carefully.